Cyclonus debuted as a wildly aggressive and unstable Decepticon warrior under Megatron during the Unicron Trilogy. He favored charging into combat with all weapons firing, laughing maniacally or yodeling, displaying minimal tactical thinking. His love for destruction made him a useful yet reckless soldier, hampered by low intelligence and a tendency to endanger allies. He frequently partnered with the Mini-Con Crumplezone, sharing enthusiasm for chaotic battles. After Megatron's initial demise, Cyclonus temporarily aligned with the Autobots against Unicron. A decade later during Energon, Cyclonus guarded Cybertron City on Earth's moon but fled during a Terrorcon attack. He briefly aided Demolishor and the Autobots on Earth until encountering Tidal Wave wielding Megatron's sword—forged from Megatron's spark by Alpha Quintesson. Believing this signaled Megatron's return, Cyclonus defected back to the Decepticons. Severely damaged in battle, he begged Megatron for repairs. An enraged Megatron instead bound him to Unicron's internal structures and forcibly reformatted him using Unicron's essence, upgrading him into a new form called Snow Cat. As Snow Cat, his alternate mode became an all-terrain snow vehicle, reflecting enhanced Arctic capabilities. He retained his erratic, battle-obsessed core personality, adopting yodeling and skiing as combat quirks. Under Scorponok's command in the Yukon, he sabotaged Autobot Base Unit 1 to reroute Energon to Unicron. He captured Omnicons and attempted reprogramming with a Spark Rewriter device, but they escaped by detonating a natural gas pocket, incapacitating him. Later, he participated in a failed raid on Ocean City to steal Omega Supreme prototype data, crashing into scaffolding and inventing a "sub-sea earthquake" story to explain his incompetence, which Megatron dismissed. Snow Cat remained loyal during the Powerlinx Battles, confronting a Super-Energon-mutated Insecticon. In the conflict's climax, after Megatron flew into a solar inferno to destroy Unicron, Snow Cat and Demolishor chose not to follow. They were last seen adrift in space, contemplating an uncertain future. In other continuities like the Dreamwave Energon comics, Snow Cat was sometimes treated as separate from Cyclonus. In one storyline, he captured Omnicons in the Yukon for Unicron's sustenance but was defeated by their teamwork. His later attempt to infiltrate Ocean City ended similarly to his animated portrayal, bungling the mission and lying about the cause. Post-Energon, ancillary materials like the Universe toy bio indicated Snow Cat descended into complete insanity after Megatron's final defeat, wandering Kaon as a raving lunatic during Cybertron's evacuation, separate from primary animated or comic narratives.